From 1947 to 1948, Barnett conducted field research on the indigenous people of Palau.

Barnett continued to study American Indians in California and the Pacific Northwest and displaced communities in the Pacific. He served as a visiting lecturer for the American Anthropological Association from 1960 until 1961. He spoke at college campuses that did not have anthropology departments, trying to spread his knowledge of anthropology.
Barnett became an emeritus professor at the University of Oregon in 1971 and officially retired in 1974. After his retirement Barnett worked on writings and publications up until the time of his death May 9, 1985.